#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <malloc.h>

int main()
{

	char *st = (char *)malloc(12 * sizeof(char));
	printf("%p\n", st);
	st = "abcd";
	printf("%p\n", st);

	strcpy(st, "abcd");  //if not ignore line 12 and line 13 , it will be wrong when running here , because address of "st" has changed to const address  when run the line 13 , and changing  const add is not permitted.
	st[1] = '2';
	printf("%p,%s\n", st, st);

}
